a = 10
b = 5
print(a + b)
# a = input('请输入第一个整数：')
# b = input('请输入第二个整数：')
# #这里 input获取的默认为字符 a + b 等于是拼接字符串
# print(f'a + b = {a + b}')
# c = input('请输入第三个整数：')
# d = input('请输入第四个整数：')
# a = float(a)
# b = float(b)
# c = float(c)
# d = float(d)
# avg = (a + b + c + d) / 4
# print(f'平均成绩为：{avg}')
print(type(a))
x = "hello world"
print(type(x))
print(x)
y = "!\nMy name is 'lei jin bao'"
print(x + y)
# x = 10
# y = 20
# print(f'{x + y}')
print(len(x))
# 字符串里面的\n和引号也算一个字符串
print(len(x + y))
#计算四个数的方差
a = 20.5
b = 30.6
c = 65.88
d = 50.89
avg = (a + b + c  + d) / 4
totle = (a - avg) ** 2 + (b - avg) ** 2 + (c - avg) ** 2 + (d - avg) ** 2
print(totle / 3)
print(a ** 0.5)
